Carboxylic acid Functionalized Cage‐Type Mesoporous Silica FDU‐12 as Support for Controlled Synthesis of Platinum Nanoparticles and Their Catalytic Applications

• Published in: Chemistry : a European journal 2018-09, Vol.24 (51), p.13540-13548
• Main Authors: Deka, Juti Rani, Budi, Canggih Setya, Lin, Chien‐Hua, Saikia, Diganta, Yang, Yung‐Chin, Kao, Hsien‐Ming
• Format: Article
• Language: English
• Subjects: Aminophenol; Ammonia; Cages; Carboxylic acids; Catalysis; Catalysts; Catalytic activity; Chemical synthesis; Chemistry; Durability; heterogeneous catalysis; Hydrogen production; Leaching; mesoporous materials; Nanoparticles; Nitrophenol; Platinum; Porous materials; Silica; Silicon dioxide; supported catalysts
• ISSN: 0947-6539; 1521-3765
• DOI: 10.1002/chem.201802146

Carboxylic acid functionalized 3D cage‐type mesoporous silica FDU‐12 with high surface area and pore volume was synthesized by a one‐pot co‐condensation method and used as support to synthesize Pt nanoparticles (NPs). The uniformly distributed COOH groups in the cage can control the growth of Pt NPs with high dispersion (Pt@CF‐12). Pt@CF‐12 was used as catalyst for the hydrolysis of ammonia borane to generate H2 and for the reduction of 4‐nitrophenol to 4‐aminophenol. The catalyst exhibits higher catalytic activity (H2 generation rate of 17.8 LH2  min−1 gcat-1 ) and lower activation energy of 30.67 kJ mol−1 compared with other Pt‐based silica catalysts due to the small size of the Pt NPs (3.5 nm) and cage‐type porous structure of the support, which allowed easy diffusion of reactants. Pt@CF‐12 has excellent durability, since the support prevented NP aggregation and leaching of NPs during catalysis. Pt@CF‐12 can convert 93 % of 4‐nitrophenol to 4‐aminophenol within 10 min. Beyond the active sites! Pt nanoparticles (NPs) were synthesized by using COOH‐functionalized FDU‐12 as support, and the resulting materials, denoted CF‐12, were used as catalysts for H2 generation from ammonia borane. Due to the 3D cage‐type mesostructure of the support and small size (3.5 nm) of the Pt NPs, the catalyst exhibits high catalytic activity. The 3D cubic mesostructure of the support allows easy accessibility of reactants, prevents Pt leaching during the catalytic reaction, and hence enhances the reaction rate.